1. Field of the Invention
One embodiment of the present invention relates to an organic compound, and a light-emitting element, a display module, a lighting module, a display device, a light-emitting device, an electronic device, and a lighting device each including the organic compound. Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. In addition, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a memory device, a method for driving any of them, and a method for manufacturing any of them.
2. Description of the Related Art
As next generation lighting devices or display devices, display devices using light-emitting elements (organic EL elements) in which organic compounds or organometallic complexes are used as light-emitting substances have been developed and reported because of their potential for thinness, lightness, high-speed response to input signals, low power consumption, and the like.
In an organic EL element, voltage application between electrodes, between which a light-emitting layer is interposed, causes recombination of electrons and holes injected from the electrodes, which brings a light-emitting substance into an excited state, and the return from the excited state to the ground state is accompanied by light emission. Since the spectrum of light emitted from a light-emitting substance depends on the light-emitting substance, use of different types of light-emitting substances makes it possible to obtain light-emitting elements which exhibit various colors.
Displays or lighting devices including organic EL elements can be suitably used for a variety of electronic devices as described above, and light emission mechanism, an element structure, and the like thereof are selected in accordance with applications or characteristics required. In the case where light emission is desired to be obtained with high efficiency, an element emitting phosphorescence may be used, and in the case where reliability has priority, fluorescence may be used. In different light emission mechanism, different element structures and different materials are used, and the performance may depend on the positional relation of a level of an orbital or an excitation level. Therefore, the number of variations of an organic compound is preferably as large as possible.
In particular, the demand for a carrier-transport material with high triplet excitation level that can be used as a host material or a transport material in a phosphorescent light-emitting element and a blue fluorescent material has been increased.
Patent Document 1 discloses an organic compound that emits excellent blue fluorescence.